By the development of the minute processing technique in the semiconductor industry, a micro electrode produced on a silicon or glass substrate is used widely in the analysis appliances such as an electro chemical detector for a liquid chromatography, and a small electrochemical sensor at the medical treatment site. Moreover, in the field of the genome analysis, in order to determine the DNA base sequence, an electrophoresis analysis is executed commonly in a minute micro channel produced on a glass substrate. Also from this view point, production of a micro electrode on a substrate is regarded as extremely important.
Such interest to the micro system is not only limited to the micro electrode but recently, production and development of a micro-total-analysis system (μ-TAS) and a micro react r, in the light of developing the analysis appliances, attracts the attention so that study is promoted actively worldwide. The μ-TAS and the micro reactor have various aspects superior to the conventional devices such as the capability of measurement and analysis with a small amount of a specimen, the portability, the realization of a low cost, or the like. Therefore, a method for introducing various structures onto a substrate is regarded as important and it is discussed more than before.
Therefore, according to the μ-TAS and the micro reactor, minute structures for providing the role of a tube and a valve in an ordinary analysis appliance or chemical reactor, needs to be produced on the substrate. As to the shaping process for a minute flow passage, it is realized by application of the conventional photolithography or etching technique. However, as to the minute valve, it is considered to be difficult to obtain practically usable one.
Since the minute valve is a portion to be driven and it is also a portion to control the flow of a specimen, high durability and accuracy are required. However, a method for providing a minute valve having the durability and accuracy required to the μ-TAS or the micro reactor has not been established. Moreover, since a valve used in an analysis appliance or chemical reactor inevitably has many parts to be the cause of leakage, choking or the like, it's difficult to keep the desired performance.
Then, the invention of the present application has b en achieved in view of the above-mentioned circumstances, and an object thereof is to provide a method for simply controlling the flow of a fluid in a micro system, without using a complicated valve structure, capable of solving the problems in the conventional technique.